fix backport of #15809

Author: vkarpov15

lib/document.js

@@ -61,6 +61,8 @@ let Embedded;
 
 const specialProperties = utils.specialProperties;
 
+const VERSION_INC = 2;
+
 /**
  * The core Mongoose document constructor. You should not call this directly,
  * the Mongoose [Model constructor](./api/model.html#Model) calls this for you.